This invention relates to a tool utilized for refilling a used, empty ampule of a dental impression material injection syringe with impression materials such as alginate.
Such ampule used with the syringe for injecting dental alginate impression materials is first explained with reference to the accompanying drawing. As illustrated in FIG. 3, an impression of a treated tooth 1 is taken by injecting an impression material a over said tooth, and according to which impression a crown to be covered over the tooth is made by casting. Said impression material a such as alginate is hermetically contained in an ampule 2 such as illustrated in FIG. 2. The ampule commonly made from glass, is a tube having an upper opening 20 and a lower neck opening 21. In a factory, the impression material is warmed and made liquid, and then charged into the tube. When it is solidified, the lower neck opening 21 of the tube is sealed by a rubber diaphragm 22 which is in turn fastened by a metal ring cap 23. A rubber plug 24 is insertedly fitted to the upper opening 20.
This tubular ampule is mounted by a dentist on the injection syringe 3, cylinder 30 of which is open at its side, whereby an injection needle 31 pierces through the rubber diaphragm 22 of ampule 2, and a piston 32 engages to the upper opening 20 of the ampule. The injection syringe 3 with the ampule 2 is warmed so as to make the impression material a softened. Then, the piston 32 is pressed downwardly, resulting in having the rubber plug 24 descended and consequently resulting in having the alginate a injected through the needle 31.
The ampule thus used and made empty has seldom been reused by a dentist, because of the following reasons.
It is nearly impossible to take out from the ampule the rubber plug 24 which has been pushed down to the bottom of the ampule (FIG. 4). Even a tool 40 such as shown in FIG. 5 which is engageable with the plug 24 by its screwed hook 40, can not successfully draw out the plug, mainly on account of a large negative pressure existing below the plug. And, even if the rubber plug 24 were to be successfully drawn out, a stick-like solid alginate can not be inserted into the ampule against air existing thereing. It shall be an idea to make the alginate liquid and pour it into the ampule, but this requires specific installations. It shall be another idea to tear down the metal ring cap 23 and refasten the lower neck opening 21 with a new cap again after the ampule has been refilled with alginate. But, this requires also specific devices.
In view of the above, this invention is to provide a simple tool which is advantageously utilized by a dentist on a small scale as he requires for manually refilling an empty ampule with dental impression materials such as alginate.